Transforming growth factor beta 2 (TGF-β2) is a member of TGF-beta superfamily that shares a characteristic cysteine knot structure. Mice with TGF-β2 gene deletion show defects in development of cardiac, lung, craniofacial, limb, spinal column, eye, inner ear and urogenital systems. All TGF-β isoforms signal via the same heteromeric receptor complex, consisting of a ligand binding TGF-β receptor type II (TβR-II), and a TGF-β receptor type I (TβR-I). Signal transduction from the receptor to the nucleus is mediated via SMADs. TGF-β expression is found in cartilage, bone, teeth, muscle, heart, blood vessels, haematopoitic cells, lung, kidney, gut, liver, eye, ear, skin, and the nervous system.